Flat panel display devices such as a liquid crystal display device and a plasma display device are favored by users because of such advantages as being light and thin. The flat panel display device in the related technology generally includes a front cover, a rear cover matched with the front cover, and a display panel clamped between the front and rear covers, the rear cover being generally provided in the middle with a rectangular window for exposing the side of the display panel where an image is displayed. However, due to the presence of the front cover, a rim is formed at the periphery of the display panel, making the size of the display device further reduced such as to be subject to restrictions in the case of a certain display size.